Three dimensional non-volatile storage with asymmetrical vertical select devices

Abstract

A three-dimensional array adapted for memory elements that reversibly change a level of electrical conductance in response to a voltage difference being applied across them. Memory elements are formed across a plurality of planes positioned different distances above a semiconductor substrate. Bit lines to which the memory elements of all planes are connected are oriented vertically from the substrate and through the plurality of planes.

Description

[0001]This application claims the benefit of U.S. Provisional Application 61 / 526,764, “Optimizing Architecture for Three Dimensional Non-Volatile Storage Device With Vertical Bit Lines,” filed on Aug. 24, 2011 and U.S. Provisional Application 61 / 423,007, “Non-Volatile Memory Having 3D Array of Read / Write Elements With Vertical Bit Lines and Laterally Aligned Active Elements and Methods Thereof,” filed on Dec. 14, 2010, both application are incorporated herein by reference in their entirety.BACKGROUND OF THE INVENTION[0002]1. Field of the Invention[0003]The present invention relates to technology for non-volatile storage.[0004]2. Description of the Related Art[0005]One example of non-volatile memory uses variable resistance memory elements that may be set to either low or high resistance states, and can remain in that state until subsequently re-set to the initial condition. The variable resistance memory elements are individually connected between two orthogonally extending conducto...

AI Technical Summary

Benefits of technology

[0005]One example of non-volatile memory uses variable resistance memory elements that may be set to either low or high resistance states, and can remain in that state until subsequently re-set to the initial condition. The variable resistance memory elements are individually connected between two orthogonally extending conductors (typically bit and word lines) where they cross each other in a two-dimensional array. The state of such a memory element is typically changed by proper voltages being placed on the intersecting conductors. Since these voltages are necessarily also applied to a large number of other unselected memory elements because they are connected along the same conductors as the selected memory elements being programmed or read, diodes are commonly connected in series with the variable resistive elements in order to reduce leakage currents that can flow through them. The desire to perform data reading and programming operations with a large number of memory elements in parallel results in reading or programming voltages being applied to a very large number of other memory elements. An example of an array of variable resistive elements and associated diodes is given in U.S. Patent Application Publication No. US 2009 / 0001344.

Problems solved by technology

The desire to perform data reading and programming operations with a large number of memory elements in parallel results in reading or programming voltages being applied to a very large number of other memory elements.

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